The Intelligent Network (IN) is an additional network constructed on the basis of an existing communication network, which rapidly introduces intelligent services to an existing network system. The intelligent services may be implemented in a switching center in the existing network system. However, most switching centers in the existing network system provide no or little intelligent service functionalities, thus the switching center in the existing network system could be upgraded to implement the intelligent services. Moreover, some intelligent services are new services in the whole network system, and are not generally limited to be in the range of an individual switching center or an individual local network. As such, all of the switching centers in the existing network system should be upgraded every time a new intelligent service is added. Since there are a large number of switching centers in the network system, it should take a long period of time as well as a lot of manpower and material resources to complete the upgrade operations.
The above-mentioned reasons lead to the generation of the IN. A characteristic of the IN is the separation of network switching from service control, in other words, the switching centers perform basic switching/connection functionalities, and a plurality of newly added functional nodes cooperate with the switching centers in the existing network system to perform new intelligent service functionalities.
Referring to FIG. 1, there is shown a block diagram illustrating a simplified structure of an IN system in a GSM mobile communication network. The IN system in the GSM mobile communication network mainly includes a Service Control Point (SCP) 20 and a Service Management System (SMS) 30, which includes a maintenance management terminal with a graphical interface, a Service Creation Environment (SCE), etc. The whole IN system provides various intelligent services using a service switching point (SSP) with a service switching capability. In the case that switching network devices have not been upgraded, the SSP exists independent of a Mobile Switching Center (MSC), thus the SSP triggers the corresponding intelligent services in the SCP 20 according to number segment or access code information, etc. of a calling/called user, such a mode for triggering intelligent services is defined as overlay network-based trigger. By contrast, in the case that the switching network devices have been upgraded, the SSP and the MSC may be arranged in the same device entity to form a MSC/SSP 10 with the service switching capability, thus the MSC/SSP 10 triggers the corresponding intelligent services in the SCP 20 according to the Origination/Termination-CAMEL Subscription Information (O/T-CSI) of the calling/called user, such a mode for triggering intelligent services is defined as target network-based trigger.
The process for operating the IN in the GSM mobile communication network shown in FIG. 1 is mainly as follows:
1) during the process in which a mobile calling user who has registered intelligent services calls a mobile called user, the MSC/SSP 10 with the service switching capability triggers the SCP 20 to provide the corresponding intelligent services according to the O/T-CSI of the calling/called user or according to the number segment or access code information, etc. of the calling/called user;
2) a service logic processing program and a service module containing service data are arranged in the SCP 20; when the MSC/SSP 10 with the service switching capability transmits a trigger message in the form of a CAMEL Application Part (CAP) message to the SCP 20, according to the trigger message, the SCP 20 performs the corresponding intelligent service logic to control the MSC/SSP 10;
3) the SCP 20 is further managed by the SMS 30. In particular, a maintenance and management terminal of the SMS 30 loads new intelligent services or upgrades existing intelligent services for the SCP 20, charges for the corresponding intelligent services used by the user, and provides the functions of operating statistics and reporting management, etc.
The IN system may provide the mobile communication network with abundant intelligent services, such as Pre-pay service, Mobile Virtual Private Network (MVPN) service, Coloring Ring Back Tone service, etc. Moreover, the IN may provide intelligent services rapidly and flexibly for users without reforming all of the switches in the network.
However, with the gradual increase of intelligent service types provided by the IN, it is inevitable that the IN have to analyze, match and process various registered intelligent services simultaneously during the process for processing the same call initiated by the same user. There is no existing specification for implementing exchange and cooperation among different SCPs to provide a service invocation capability. Thus, overlap functions of the services cannot be provided by a simple combination of the services, and thus it is inevitable that the various intelligent services are entangled and interlaced with each other because the IN analyzes and processes them simultaneously. This leads to an increased complexity of logic processing of the intelligent services and an influence of the upgrading of a certain service on the other intelligent services. Therefore, all of these aspects have a negative impact on the development of the IN system.
Nowadays, there are mainly two modes for invoking services in the IN, which are herein defined as primary trigger and secondary trigger, respectively. Simplified processes for invoking services in the above two modes will be respectively described hereinafter.
Referring to FIG. 2, which is a schematic diagram illustrating a process for invoking services by means of primary trigger in a IN, the process includes the following steps:
a mobile calling user calls a mobile called user;
the MSC/SSP 10 with the service switching capability triggers the SCP 20 to provide the corresponding intelligent service according to the O/T-CSI of the calling/called user or according to the number segment or access code information, etc. of the calling/called user;
the SCP 20 processes the call initiated by the calling user, and invokes the corresponding intelligent services according to the trigger message transmitted from the MSC/SSP 10;
the SCP 20 controls the MSC/SSP 10 to process a session between the calling user and the called user by executing the invoked intelligent service logic, the call is released when the session ends, then the session is billed in the SCP 20.
the MSC/SSP 10 triggers a single SCP 20 every time a service invocation is performed by means of the primary trigger, i.e., all service invocations would be processed in that SCP 20, thus, in the case that the user has registered multiple intelligent services, the SCP 20 would suffer from a high complexity of logic processing due to the simultaneous invocations of multiple services. Moreover, since the techniques implemented in the SCP 20 are generally manufacturer-specific, the simultaneous invocations of multiple services implemented in that SCP 20 would be accomplished by a single manufacturer. As a result, the process for invoking multiple services simultaneously by means of the primary trigger has a relatively low degree of compatibility.
Referring to FIG. 3, which is a schematic diagram illustrating a process for invoking services by means of secondary trigger in a IN, the process mainly includes the following steps:
The MSC/SSP 10 with the service switching capability triggers the SCP 20 to provide the corresponding intelligent services according to the O/T-CSI of the calling/called user or according to the number segment or access code information, etc. of the calling/called user;
the SCP1 20 invokes the corresponding intelligent services according to the trigger message transmitted from the MSC1/SSP1 10, and controls the MSC1/SSP1 10 to trigger the MSC1/SSP1 10 to perform a call connection by executing the corresponding invoked service logic;
the MSC1/SSP1 10 routes the call to the SSP2 101 according to the prearranged route data;
the SSP2 101 triggers the SCP2 20′ for the second time to provide the corresponding intelligent services according to the number segment or access code information etc. of the calling/called user (in this case, the trigger for the second time would be of the overlay network-based trigger due to the existence of the route data);
the SCP2 20′ invokes the corresponding intelligent services according to the trigger message transmitted from the SSP2 101, and controls the SSP2 101 to trigger the SSP2 101 to perform the call connection by executing the corresponding invoked service logic;
a session is established between the calling user and the called user under the controls of both the SCP1 20 and the SCP2 20′, the call is released when the session ends, then the session is billed both in the SCP1 20 and SCP2 20′.
Each of the above-mentioned SCPs is used for processing one part of the intelligent service logic invocation by the calling/called user. For example, the SCP1 20 provides a pre-paid intelligent service logic, and the SCP2 20′ provides an IP card number intelligent service logic. If the calling/called user uses a pre-paid service (PPS), as well as an IP card number service in the current call, the SCP1 20 is triggered to invoke the pre-paid intelligent service logic, and the SCP2 20′ is triggered to invoke the IP card number intelligent service logic during the call connection. Therefore, such a mode for invoking services is defined as secondary trigger.
However, according to a trigger rule, the trigger according to the O/T-CSI of the user is generally superior to the trigger according to the number segment or access code information of the user. As a result, this mode is more suitable for the secondary trigger in which the trigger for the first time is of the target network-based trigger and the trigger for the second time is of the overlay network-based trigger, therefore, it has a relatively low degree of compatibility;
Furthermore, it is required to arrange route data in the MSC1/SSP1 10 with the service switching capability, which is connected to the first SCP 20 of the SCPs 20. Also, voice channel alternation necessarily exists during the process for routing the voice channel from the MSC1/SSP1 10 to another SSP 101. If the calling user and called user are located in the same location, while the SSP 101 is located in a different location, there will be long-distance voice channel alternations from the MSC1/SSP1 10 to the SSP 101 and from the SSP101 to the MSC2 102 (referring to FIG. 3).